I think Floyd against a Roy Jones...I think he gets decimated in like 4 rounds. Never fought anyone with those angles or that speed...he would eat power hooks trying the shoulder roll.Pac in his prime you could argue. The Pac that fought Floyd.... not HALF the fighter a prime Roy was.
Roy wins easily vs Floyd, better power, better reflex/agility, more dynamic offense. Sure maybe Floyd would survive on defense and smart boxing, but not to the degree that he outpoints Roy.